Description du projet
Des études théoriques et informatiques pour mieux comprendre les instabilités élastiques
Les déformations élastiques, des changements réversibles dans les matériaux sous l’effet des forces qui s’exercent sur eux, sont omniprésentes dans la nature et dans les matériaux d’ingénierie. Parfois, lorsque les matériaux subissent des déformations dont la force est relativement importante par rapport à la force de restauration, ils peuvent développer ce que l’on appelle des instabilités élastiques, et de nouvelles formes apparaissent. Ce phénomène se traduit par des rides sur la peau ou la rupture d’un parapluie par grand vent. Le projet GADGET, financé par le Conseil européen de la recherche, développera un cadre théorique permettant de combler les lacunes dans notre compréhension des instabilités élastiques. Il utilisera un système modèle, une coque élastique sous pression soumise à une déformation géométrique importante, afin de déterminer le rôle joué par la géométrie et la dynamique.
Objectif
Elastic instabilities are ubiquitous, from the wrinkles that form on skin to the ‘snap-through’ of an umbrella on a windy day. The complex patterns such instabilities make, and the great speed with which they develop, have led to a host of technological and scientific applications. However, recent experiments have revealed significant gaps in our theoretical understanding of such instabilities, particularly in the roles played by geometry and dynamics. I will establish a group to develop and validate a theoretical framework within which these results can be understood. Central to my approach is an appreciation of the crucial role of geometry in the pattern formation and dynamics of elastic instabilities.
As a starting point, I will consider the model problem of a pressurized elastic shell subject to a geometrically large deformation. This system develops either wrinkles or a stress-focusing instability depending on the internal pressure. As such, this is a natural paradigm with which to understand geometrical features of deformation relevant across length scales from deformed viruses to the subduction zones in Earth’s tectonic plates. My team will combine theoretical and computational approaches with tabletop experiments to determine a new set of shell deformations that are generically observed in contradiction of the classic ‘mirror buckling’. Understanding why these new shapes emerge will transform our perception of shell instabilities and provide new fundamental building blocks with which to model them. These ideas will also be used to transform our understanding of a number of other, previously mysterious, elastic instabilities of practical interest. Turning our focus to the dynamics of instabilities such as the snap-through of shells, we will show that accounting for geometry is again crucial. The new insight gained through this project will increase our ability to control elastic instabilities, benefitting a range of technological and scientific applications.
Champ scientifique
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
OX1 2JD Oxford
Royaume-Uni